In recent years, the number of devices operating using wireless communication has been increased in audio visual (AV) devices and wireless transmission of sound is performed by using WiFi (registered trademark, the same applies hereinafter), ZigBee (registered trademark, the same applies hereinafter), and Bluetooth (registered trademark, the same applies hereinafter). However, compressed sound is a subject of current audio wireless transmission.
Since compressed sound is a subject of current audio wireless transmission as described above, it is not yet necessary to perform evaluation of sound quality. However, when audio devices are connected by radio, usability is improved, and therefore, the realization of wireless communication is also promoted for high-level audio devices requiring high sound quality. For example, Wireless Speaker and Audio (WiSA) Association has proceeded with standardization of technologies of wirelessly transmitting audio signals by decompressed pulse code modulation (PCM).
Meanwhile, particularly in high-level audio devices, large electric power is consumed due to high wattage or the like, and accordingly, the audio devices may be seriously damaged or broken due to a minute flaw. Thus, an overcurrent countermeasure is necessary particularly for high-level audio devices.
PTL 1, for example, discloses a technology for an overcurrent countermeasure of an audio wireless transmission system. In the technology disclosed in PTL 1, a device on an audio reception side includes a power amplifier which amplifies electric power, and a power source circuit in which a small cell for power amplifier driving and an electric double layer capacitor are arranged in parallel, and accordingly, a long-term operation can be performed even with a small cell and an overcurrent due to a rapid change of audio signals can be controlled.